894 results about "Carbon substrate" patented technology

The invention discloses a carbon/silicon/carbon nano composite structure cathode material and a preparation method thereof, belonging to the technical field of electrochemical power supply technologies. The cathode material consists of a carbon-based conductive substrate, nano silicon and a nano carbon coating layer, wherein the nano silicon is uniformly distributed on the carbon-based conductive substrate; the nano carbon coating layer is arranged on the surface of the nano silicon; the carbon-based conductive substrate is porous carbon, a carbon nanotube or graphene; the nano silicon exists in the state of nanoparticles or nano films; the weight percentage of the nano silicon in the cathode material is 10-90 percent; and the thickness of the nano carbon coating layer is 0.1-10 nanometers. The preparation method comprises the following steps of: depositing nano silicon on the carbon substrate in a reaction space in oxygen-free atmosphere by adopting a chemical vapor deposition process; and coating nano carbon on the surface of the nano silicon by adopting the chemical vapor deposition process. In the obtained carbon/silicon/carbon composite cathode material, the volume change of a silicon electrode material is controlled effectively in the charging and discharging processes, the electrode structure is kept complete, the circulation volume is large, the circulation service life is long, and the electrochemical performance is high.

Recombinant hosts for producing polyhydroxyalkanoates and methods of producing polyhydroxyalkanoates from renewable carbon substrates are provided. Certain recombinant hosts that produce 5 carbon chemicals such as 5-aminopentanoate (5AP), 5-hydroxyvalerate (5HV), glutarate, and 1,5 pentanediol (PDO) are also provided. One embodiment provides a recombinant host expressing a gene encoding a heterologous enzyme selected from the group consisting of a polyhydroxyalkanoate synthase and a 5-hydroxyvalerate-CoA (5HV-CoA) transferase, wherein the host produces a polymer containing 5-hydroxyvalerate. Preferably, the host expresses both a polyhydroxyalkanoate synthase and a 5HV-CoA transferase. The host can be prokaryotic or eukaryotic. A preferred prokaryotic host is E. coli. The polymers produced by the recombinant hosts can be homopolymers or copolymers of 5-hydroxyvalerate. A preferred copolymer is poly(3-hydroxybutyrate-co-5-hydroxyvalerate).

The invention provides a non-naturally occurring set of microbial organisms. The set of organisms includes: at least a first constituent complementary metabolizing organism (CMO) exhibiting the ability to metabolize a first carbon substrate and having substantially impaired metabolic capacity for a second carbon substrate, and at least a second constituent complementary metabolizing organism (CMO) exhibiting the ability to metabolize the second carbon substrate and having substantially impaired metabolic capacity for the first carbon substrate, wherein a co-culture of the at least first and second CMOs exhibit simultaneous metabolism of a mixture having the first and second carbon substrates compared to either CMO alone. Simultaneous metabolism of a mixture having first and second carbon substrates can include an enhanced rate of metabolism of the first and second substrates compared to either CMO alone. Also provided is a bioprocess for producing a chemical compound. The bioprocess includes co-culturing a non-naturally occurring set of microbial organisms in a mixture having at least a first and a second carbon substrate under conditions sufficient for biosynthesis of a target chemical compound, the set of non-naturally occurring microbial organisms including: at least a first constituent complementary metabolizing organism (CMO) exhibiting the ability to metabolize the first carbon substrate and having substantially impaired metabolic capacity for the second carbon substrate, and at least a second constituent complementary metabolizing organism (CMO) exhibiting the ability to metabolize the second carbon substrate and having substantially impaired metabolic capacity for the first carbon substrate, wherein a co-culture of the at least first and second CMOs exhibit simultaneous metabolism of a mixture having the first and second carbon substrates compared to either CMO alone. Simultaneous metabolism of a mixture having first and second carbon substrates can include an enhanced rate of metabolism of the first and second substrates compared to either CMO alone.

A method for making a carbon-metal-nitrogen oxygen reducing cathode catalyst, the method comprising mixing a carbon source with a transition metal precursor to form a metal precursor loaded carbon substrate; adding a nitrogen precursor compound to the metal precursor loaded carbon substrate to form a carbon-metal-nitrogen precursor; and pyrolyzing the carbon-metal-nitrogen precursor in a closed vessel, thereby forming an oxygen reducing cathode catalyst. The carbon-metal-nitrogen catalyst requires no precious metal such as Pt, and also provides benefits such as controlled deposition of catalytically active nitrogenous compounds that can increase the catalytic activity of the catalyst when compared to gaseous deposition of nitrogen to the surface of the carbon support.

Recombinant organisms are provided comprising genes encoding a glycerol-3-phosphate dehydrogenase and/or a glycerol-3-phosphatase activity useful for the production of glycerol from a variety of carbon substrates. The organisms further contain disruptions in the endogenous genes encoding proteins having glycerol kinase and glycerol dehydrogenase activities.

An aromatic dicarboxylic acid is purified by oxidizing m-xylene or p-xylene to produce crude isophthalic acid or crude terephthalic acid, respectively. The products of the oxidizing step are hydrogenated in the presence of a palladium catalyst. Carbon monoxide is introduced during the hydrogenation step. The palladium catalyst is provided on a carbon substrate. The products of the oxidizing step are dissolved in a solvent, which may be water, prior to the hydrogenation step. The products of the oxidizing step may be dissolved at an elevated temperature, above the normal boiling point of the solvent. The oxidation step produces isophthalic acid, 3-carboxybenzaldehyde and fluorenones in the case of oxidizing m-xylene and produces terephthalic acid, 4-carboxybenzaldehyde and fluorenones in the case of oxidizing p-xylene. It may be helpful to monitor the disappearance of 3-carboxybenzaldehyde in the case of oxidizing m-xylene and 4-carboxybenzaldehyde in the case of oxidizing pxylene, and reducing the amount of carbon monoxide when the rate of disappearance is below a predetermined minimum. After the hydrogenation step, the isophthalic acid or terephthalic acid may be crystallized. The carbon monoxide may be maintained at a concentration of 100 to 500 ppm based on added hydrogen and carbon monoxide. Other aromatic dicarboxylic acids may also purified by this procedure.

A current collector of a battery includes a reticulated substrate having a circuitous network of pores and a metal applied to at least a portion of the reticulated substrate. The reticulated substrate may be a non-metal foam substrate, such as, for example, a carbon foam substrate, a reticulated vitreous carbon substrate or a graphite foam substrate.

The invention relates to a resin isobaric liquid-phase impregnation densification method for rapidly filling pores inside a carbon/carbon composite material. The method comprises the following steps of by using a PIP (precursor impregnation and pyrolysis) process and a vacuum autoclave with an isobaric impregnation recovery device, and taking nitrogen as a protective gas, using an impregnating solution to impregnate a carbon fiber perform or low-density C/C body workpiece in a vacuum; allowing the impregnating solution to infiltrate into the workpiece at nitrogen pressure; isobarically recovering excess impregnating solution; continuing to isobarically heat to thermally set resin; and then carbonizing the resin into a carbon substrate for filling the pores inside the workpiece. The carbon/carbon composite material component with the required density is obtained by multiple circulating operations. The period of the method is short, and the excess impregnating solution which does not filtrate into the workpiece is isobarically recovered, so that the resin is prevented from reversely filtrating, the resin consumption and pure nitrogen consumption are reduced, and the densification efficiency and the densification uniformity are improved.

Embodiments include a method and apparatus for recovering ammonia and nitrogen from a waste stream. Embodiments further include recovering ammonia using an ammonia recovery process and a biological nitrogen recovery process. In some embodiments, a return stream from the ammonia recovery process may be used to provide alkalinity, carbon substrate, and/or biological oxygen demand to the biological nitrogen recovery process. In some embodiments, a hydrothermal sludge process may be used to further treat the waste stream and provide additional return to the ammonia recovery system. Other embodiments include an ammonia recovery system for conducting the ammonia recovery process, a biological nitrification and/or denitrification system for conducting the biological nitrogen recovery process, and an optional hydrothermal sludge processing system.

The present invention discloses an improved electrode for a supercapacitor and a method of preparation thereof. The inventive electrode comprises a collector, a carbon substrate disposed on the collector comprising ultrafine carbon fibers having a specific surface area of at least 200 m²/g (BET) and a d₀₀₂ value of 0.36 nm or less, and a metal oxide thin layer formed on the carbon substrate. The electrode of the subject invention retains a high specific capacitance during high-speed charging and discharging cycles.

The invention discloses application and a preparation method of biomass-based nitrogen-doped porous carbon. The method includes: taking cheap cellulose carbamate as a raw material and urea as a nitrogen source, well mixing with sodium hydroxide solution, drying to form sol, and performing high-temperature calcination to obtain the porous-structure biomass-based nitrogen-doped porous carbon high in specific surface area and pore volume. According to electron microscopy images, the prepared material is in a three-dimensional inner-crosslinked porous structure; according to XPS and elemental analysis, nitrogen is successfully doped into a carbon substrate, the nitrogen content is 7.7-15.5%, and the specific surface area is 700-3700m<2>/g; according to supercapacitor experiments, the biomass-based nitrogen-doped porous carbon is great in electrochemical performance; according to pollutant adsorption experimental data, the material is high in adsorption rate and adsorption capacity in adsorption of dye pollutant methylene blue, and the adsorption capacity reaches 1520mg/g. The method is simple in preparation, the raw materials are renewable, and low cost is realized. In addition, sodium carbonate which is a by-product is obtained by washing of calcined samples, so that cost can be effectively reduced, and economic benefits are increased.

The invention discloses a nitrogen-enriched carbon base/sulfur composite cathode material used for lithium sulphur batteries, and a preparation method thereof, and belongs to the field of new generation energy storage. The nitrogen-enriched carbon-based/sulfur composite cathode material comprises a nitrogen-enriched porous carbon-based carrier prepared by taking fibroin as a nitrogen-rich carbon source, and a conductive network, possesses large specific surface area, high porosity, and excellent electrical conductivity; the nitrogen-enriched porous carbon-based carrier is activated with potassium hydroxide; and the nitrogen-enriched carbon base/sulfur composite cathode material is prepared via holt melting sulfur filling. The preparation method is simple, is friendly to the environment, and is suitable for industrialized production; the nitrogen-enriched carbon base/sulfur composite cathode material used for lithium sulphur batteries possesses high energy density, excellent cycling performance, and excellent rate capability, and possesses wide application prospect in the fields such as mobile communication and portable digital products, electric automobiles, and energy storage devices.

The invention provides a polyaniline-manganese dioxide-titanium nitride nanowire array composite material which comprises a carbon substrate (1), a titanium nitride nanowire array (2), a villiform manganese dioxide nano-film (3) and a coralliform polyaniline nanofiber (4). The titanium nitride nanowire array (2) is perpendicularly arranged on the surface of the carbon substrate (1) and connected with the carbon substrate (1) to form an integral structure, the manganese dioxide nano-film (3) coats the surface of the titanium nitride nanowire array (2), and the coralliform polyaniline nanofiber (4) is adhered on the surface of the manganese dioxide nano-film (3). The invention further provides a preparation method of the composite material and application of the composite material in a supercapacitor. The polyaniline-manganese dioxide-titanium nitride nanowire array composite material has features of an orderly-arranged porous structure, is regular and controllable in shape and appearance, can be directly applied to an electrode material of the supercapacitor and has wide actual application value and industrial production prospect.

Provided herein are glycerol-3-phosphate dehydrogenase (GPD) enzymes with increased K_M for NADH and GPD enzymes with substantially the same affinity for NADH and NADPH and/or are feedback inhibited by glycerol-3-phosphate. Also provided herein are recombinant microorganisms comprising a heterologous gene encoding GPD and a deletion or disruption in an endogenous gene encoding GPD. Also provided are recombinant microorganisms comprising a heterologous gene encoding GPD and a butanol biosynthetic pathway. Further provided are methods of producing butanol comprising providing the recombinant microorganisms described herein and contacting the recombinant microorganism with at least one fermentable carbon substrate under conditions wherein butanol is produced.

Techniques for forming a thin coating of a material on a carbon-based material are provided. In one aspect, a method for forming a thin coating on a surface of a carbon-based material is provided. The method includes the following steps. An ultra thin silicon nucleation layer is deposited to a thickness of from about two angstroms to about 10 angstroms on at least a portion of the surface of the carbon-based material to facilitate nucleation of the coating on the surface of the carbon-based material. The thin coating is deposited to a thickness of from about two angstroms to about 100 angstroms over the ultra thin silicon layer to form the thin coating on the surface of the carbon-based material.

The invention discloses a sulfur/carbon composite material for a lithium-sulfur secondary battery and a preparation method thereof. The composite material is formed by compositing a micro-pore carbon substrate with a lithium ion conduction property and elemental sulfur filled in the micro-pore structure. The carbon substrate is used as an electronic conductor in the composite material, and is further used as a lithium ion conductor, so that sulfur electrode reaction is directly carried out on a sulfur/carbon solid-solid interface in a conversion reaction manner without directly contacting with electrolyte. Therefore, the problem of circulation caused by that a polysulfide intermediate product is dissolved in the electrolyte can be solved. Compared with the other sulfur/carbon composite electrode, the composite material has the advantages of high electrochemical capacity, good circulation stability, high charging and discharging efficiency and the like; and meanwhile, the preparation method is simple and low in cost, and has a good application prospect.

The invention provides an active carbon-based material and a preparation method thereof. The carbon-based material comprises the following components based on parts by weight percent: 50-90% of carbon, 0.1-35% of oxygen, 0.1-35% of nitrogen, 0.0%-10% of sulphur, 0.0%-15% of phosphorus and 0.0-15% of boron. The preparation method comprises the following step of carbonizing doped or undoped polyaniline polymer at 500-1200 DEG C for 1-24h under the protection of inert gas. Heteroatom N, O, S, P, B, H and group thereof are induced to the carbon atom to change the chemical environment of the carbon atom and increase the space charge density of the carbon atom and the polarity of the material, so that the material has surface standard faraday capacitance and double electric layer capacitance, and has higher specific capacity, good electrical conductivity, and higher energy density and power density under the condition that the specific surface area is not increased. The preparation method of the active carbon-based material has the advantages of simple technology, easily-obtained raw materials, low cost, small pollution and being capable of being produced on a large scale.

The invention provides a vanadium selenide/carbon-based composite material, a preparation method of the material, and a negative electrode of a lithium ion battery. Vanadium selenide in the vanadium selenide/carbon-based composite material is of a hexagonal crystal system and is deposited on the surface of a carbon-based material, or the surfaces of vanadium selenide particles are at least partially coated with the carbon-based material to form vanadium selenide/carbon particles of a core shell-like structure; the vanadium selenide/carbon particles are connected through carbon nets to obtain the high conductivity. In the negative electrode of the power lithium ion battery, prepared from the vanadium selenide/carbon-based composite material provided by the invention, since selenide with the relatively large specific capacity is combined with the carbon-based material, the negative electrode has the characteristics of large capacity, high rate and high cyclic stability. Therefore, the negative electrode made of the composite material has the relatively large capacity, relatively long service life and relatively low price when applied to the lithium ion battery.

Tantalum-based ceramics are suitable for use in thermal protection systems. These composite structures have high efficiency surfaces (low catalytic efficiency and high emittance), thereby reducing heat flux to a spacecraft during planetary re-entry. These ceramics contain tantalum disilicide, molybdenum disilicide and borosilicate glass. The components are milled, along with a processing aid, then applied to a surface of a porous substrate, such as a fibrous silica or carbon substrate. Following application, the coating is then sintered on the substrate. The composite structure is substantially impervious to hot gas penetration and capable of surviving high heat fluxes at temperatures approaching 3000° F. and above.

Recombinant organisms are provided comprising genes encoding aquacobalamin reductase, cob(II)alamin reductase, cob(I)alamin adenosyltransferase, glycerol dehydratase and 1,3-propanediol oxidoreductase activities useful for the production of 1,3-propanediol from a variety of carbon substrates. More specifically the following nucleotide sequences are provided: btuR, encoding the E. coli cob(I)alamin adenosyltransferase enzyme; cobA, encoding the Salmonella typhimurium cob(I)alamin adenosyltransferase enzyme; cobO, encoding the Pseudomonas denitrificans cob(I)alamin adenosyltransferase enzyme; dhaB1, encoding the α subunit of the Klebsiella glycerol dehydratase enzyme; dhaB2, encoding the β subunit of the Klebsiella glycerol dehydratase enzyme; dhaB3, encoding the γ subunit of the Klebsiella glycerol dehydratase enzyme; dhaT, encoding Klebsiella oxidoreductase enzyme; the yciK gene isolated from E. coli; the glucose isomerase promoter sequence from Streptomyces; and the N-terminal amino acid sequence for cob(II)alamin reductase from Pseudomonas denitrificans.

The invention relates to a cathode material used for a lithium-sulfur secondary battery. The cathode material is characterized in that transition metal nitrides are contained in the cathode material. The transition metal nitrides are anchored on the surface of a carbon substrate well to form a conductive network together by using higher conductivity of the transition metal nitrides and affinity with the carbon substrate; moreover, the redox liquid phase conversion reaction speed of a polysulfide intermediate product is strengthened in the cathode reaction process of the lithium-sulfur battery by using the polarity characteristics of the metal nitrides, the utilization rate of the sulfur active material in the lithium-sulfur battery is improved, and the cathode material is beneficial for promoting the practicability of sulfur in the lithium-sulfur secondary battery.